P
US7934379B2ExpiredUtilityPatentIndex 82

Internal combustion engine comprising an exhaust gas turbocharger

Assignee: DAIMLER AGPriority: Jul 15, 2004Filed: Jan 9, 2007Granted: May 3, 2011
Est. expiryJul 15, 2024(expired)· nominal 20-yr term from priority
Inventors:KUESPERT ALFREDSCHMID WOLFRAMSUMSER SIEGFRIED
F02D 9/06F02M 26/05F02B 37/12F05B 2220/40F02B 37/025F02B 37/22F02B 37/183F02B 29/0406F02B 37/24F02M 26/23Y02T10/12
82
PatentIndex Score
19
Cited by
10
References
16
Claims

Abstract

In an internal combustion engine comprising an exhaust gas turbocharger, including a turbine with at least two inlet passages arranged in the exhaust gas tract of the internal combustion engine, via which exhaust gas from the internal combustion engine can be supplied to a turbine wheel of the turbine, and a valve arrangement being arranged in to the exhaust gas tract to the turbocharger to control the supply of exhaust gas to the inlet passages of the turbine, a valve and turbine inlet passage configuration is selectable providing for a maximum braking power with low thermal load.

Claims

exact text as granted — not AI-modified
1. An internal combustion engine comprising an exhaust gas turbocharger, said engine having at least one variable-volume combustion chamber, and an exhaust gas tract ( 4 ) extending from the combustion chamber, said combustion chamber having a total piston displacement volume V 11  that can be determined by the difference between a minimum and a maximum combustion chamber volume, said exhaust gas turbocharger ( 20 ) including a turbine ( 3 ) arranged in the exhaust gas tract ( 4 ) of the internal combustion engine ( 100 ) with a turbine wheel ( 12 ) having a diameter D T  and with at least two inlet passages ( 6 ,  7 ) and a neck cross section A l  in which the inlet passages ( 6 ,  7 ) end in at least two annular nozzles with flow cross-sections of different size, and through which exhaust gas can be supplied to the turbine wheel ( 12 ) via the inlet passages ( 6 ,  7 ), and a valve arrangement ( 50 ) with a flow cross-section dA Ab , which is adjustable between a minimum opening cross-section dA Ab,min  and a maximum opening cross-section dA Ab,max  being provided in the exhaust gas tract ( 4 ) to the turbine ( 3 ), for diverting exhaust gas from one inlet passage ( 6 ,  7 ) into the other inlet passage ( 7 ,  6 ) or blowing exhaust gas off past the turbine wheel ( 12 ), wherein based on an engine braking mode at maximum braking power of the internal combustion engine  100 ,
 the diameter D T  of the turbine wheel  12 , 
 the piston displacement V H  of the internal combustion engine  100 , 
 a smallest flow cross section A D,small  to the turbine wheel  12 , and 
 the maximum opening cross section dA Ab,max  of a diverting opening (X) of the valve arrangement ( 50 ) which determines a turbocharger braking factor TBF asym  are related to one another as follows: 
 
       
         
           
             
               
                 TBF 
                 Asym 
               
               = 
               
                 
                   ( 
                   
                     
                       A 
                       
                         D 
                         , 
                         small 
                       
                     
                     + 
                     
                       dA 
                       
                         Ab 
                         , 
                         max 
                       
                     
                   
                   ) 
                 
                 · 
                 
                   
                     D 
                     T 
                   
                   
                     V 
                     H 
                   
                 
               
             
           
         
         where the turbocharger braking factor TBF asym  is smaller than 0.005, and the smallest flow cross-section A D,small  at maximum braking power corresponds to:
   A D,small  =A D,1    
 
         if the neck cross-section A l  being is larger than the smallest annular nozzle cross section A D,1  or the smallest annular nozzle flow cross-section A D,small  at maximum braking power corresponds to:
   A D,small  =A l    
 
         if the neck flow cross-section A 1  is smaller than the smallest annular nozzle cross section A D,l . 
       
     
     
       2. The internal combustion engine at claimed in  claim 1 , wherein the ratio V A  of the maximum variable opening cross section dA Ab,max  to the smallest flow cross section A D,small  at maximum braking power corresponds to: 
       
         
           
             
               
                 V 
                 A 
               
               = 
               
                 
                   
                     dA 
                     
                       Ab 
                       , 
                       max 
                     
                   
                   
                     A 
                     
                       D 
                       , 
                       small 
                     
                   
                 
                 > 
                 
                   0.2 
                   . 
                 
               
             
           
         
       
     
     
       3. The internal combustion engine as claimed in  claim 2 , wherein the value of the opening cross section dA Ab,max  of the diversion opening (X) of the valve arrangement ( 50 ) at maximum braking power is the upper limit value that the opening cross section dA Ab  of the diversion opening (X) of the valve arrangement ( 50 ) can assume. 
     
     
       4. The internal combustion engine as claimed in  claim 3 , wherein the value of the maximum opening cross-section dA Ab,max  of the diversion opening (X) of the valve arrangement ( 50 ) does not exceed the value of a largest annular nozzle cross-section. 
     
     
       5. The internal combustion engine as claimed in  claim 4 , wherein the opening cross section dA Ab  of the diversion opening (X) of the valve arrangement ( 50 ) is variable according to the engine speed. 
     
     
       6. The internal combustion engine as claimed in  claim 5 , wherein the opening cross section dA Ab  of the diversion opening (X) of the valve arrangement ( 50 ) is reduced with falling engine speed. 
     
     
       7. The internal combustion engine as claimed in  claim 6 , wherein the range of the opening cross-section dA Ab  of the diversion opening (x) assigned to an. upper range of an engine speed band extends at least up to the engine speed at maximum braking power. 
     
     
       8. The internal combustion engine as claimed in  claim 7 , wherein the maximum braking power is at an engine speed that is higher than the rated. engine speed of the internal combustion engine ( 100 ). 
     
     
       9. The internal combustion. engine as claimed in  claim 8 , wherein the engine speed range in which the opening cross section dA Ab  of the diversion opening (X) of the valve arrangement ( 50 ) is uncovered begins at roughly ⅔ to ¾ of the engine speed at maximum braking power. 
     
     
       10. The internal combustion engine as claimed in  claim 9 , wherein the maximum braking power lies at an engine speed that is roughly ¼ to ⅓ higher than the rated engine speed of the internal combustion engine ( 100 ). 
     
     
       11. An internal combustion engine comprising an exhaust gas turbocharger, said engine having at least one variable-volume combustion chamber, and an exhaust gas tract ( 4 ) extending from the combustion chamber, said combustion chamber having a total piston displacement volume V H  that can be determined by the difference between a minimum and a maximum combustion chamber volume, said exhaust gas turbocharger ( 20 ) including a turbine ( 3 ) arranged in the exhaust as tract ( 4 ) of the internal combustion engine ( 100 ) with a turbine wheel ( 12 ) having a diameter D T  and with at least two inlet passages ( 6 ,  7 ) and a neck cross section A 1  in which the inlet passages ( 6 ,  7 ) end in at least two annular nozzles with flow cross-sections of different size, and through which exhaust gas can be supplied to the turbine wheel ( 12 ) via the inlet passages ( 6 ,  7 ), and a valve arrangement ( 50 ) with a flow cross-section dA Ab,  which is adjustable between a minimum opening cross-section dA Ab,min  and a maximum opening cross-section dA Ab,max  being provided in the exhaust gas tract ( 4 ) to the turbine ( 3 ), for diverting exhaust gas from one inlet passage ( 6 ,  7 ) into the other inlet passage ( 7 ,  6 ) or blowing exhaust gas off past the turbine wheel ( 12 ), wherein based on an engine braking mode at maximum braking power of the internal combustion engine ( 100 ),
 the diameter D T  of the turbine wheel ( 12 ), 
 the piston displacement V H  of the internal combustion engine ( 100 ), 
 a smallest flow cross section A D,small  to the turbine wheel ( 12 ) , and 
 the maximum opening cross section dA Ab,max  of a diverting opening (X) of the valve arrangement ( 50 ) which determines a turbocharger braking factor TBF asym  are related to one another as follows: 
 
       
         
           
             
               
                 TBF 
                 Asvm 
               
               = 
               
                 
                   ( 
                   
                     
                       A 
                       
                         D 
                         , 
                         small 
                       
                     
                     + 
                     
                       dA 
                       
                         Ab 
                         , 
                         max 
                       
                     
                   
                   ) 
                 
                 · 
                 
                   
                     D 
                     T 
                   
                   
                     V 
                     H 
                   
                 
               
             
           
         
         where the turbocharger braking factor TBF asym  is smaller than 0.005, and the smallest flow cross-section A D,small  at maximum braking power corresponds to:
   A D,small =A D,1    
 
         if the neck cross-section A 1  is larger than the smallest annular nozzle cross section A D,1  or the smallest annular nozzle flow cross-section A D,small  at maximum braking power corresponds to:
   A D,sma11=A   1    
 
         if the neck flow cross-section A 1  is smaller than the smallest annular nozzle cross section A D,1 , 
         wherein an asymmetry factor F Asym  characterizing the ratio of sizes of the inlet passages ( 6 ,  7 ) of the turbine ( 3 ) as a function of the piston displacement V V11  of the internal combustion engine ( 100 ) follows the equation 
       
       
         
           
             
               
                 F 
                 Asym 
               
               ≤ 
               
                 
                   ( 
                   
                     1 
                     
                       V 
                       H 
                     
                   
                   ) 
                 
                 0.15 
               
             
           
         
         the asymmetry factor F Asym  being defined according to the equation 
       
       
         
           
             
               
                 F 
                 Asym 
               
               = 
               
                 
                   ϕ 
                   
                     31 
                     , 
                     S 
                   
                 
                 
                   ϕ 
                   
                     32 
                     , 
                     S 
                   
                 
               
             
           
         
         and φ 31,s  and φ 32,s  defining turbine throughput parameters in the range of the choke line S of the turbine ( 3 ) that can be calculated from the equation 
       
       
         
           
             
               
                 ϕ 
                 
                   31 
                   , 
                   S 
                 
               
               = 
               
                 
                   
                     m 
                     . 
                   
                   
                     31 
                     , 
                     S 
                   
                 
                 ⁢ 
                 
                   
                     
                       T 
                       
                         31 
                         , 
                         S 
                       
                     
                   
                   · 
                   
                     1 
                     
                       p 
                       
                         31 
                         , 
                         S 
                       
                     
                   
                 
               
             
           
         
         
           
             
               
                 ϕ 
                 
                   32 
                   , 
                   S 
                 
               
               = 
               
                 
                   
                     m 
                     . 
                   
                   
                     32 
                     , 
                     S 
                   
                 
                 ⁢ 
                 
                   
                     
                       T 
                       
                         32 
                         , 
                         S 
                       
                     
                   
                   · 
                   
                     1 
                     
                       p 
                       
                         32 
                         , 
                         S 
                       
                     
                   
                 
               
             
           
         
         wherein {dot over (m)} 31,s  and {dot over (m)} 32,s  refer to the exhaust gas mass flow through the first and second inlet passages ( 6 ,  7 ) respectively in the range of the choke line S of the turbine ( 3 ), T 31,s , T 32,s  to the exhaust gas temperatures in the first and second inlet passages ( 6 ,  7 ) respectively in the range of the choke line S of the turbine ( 3 ), and p 31,G , p 32,s  to the exhaust gas pressures in the first and second inlet passages ( 6 ,  7 ) respectively in the range of the choke line S of the turbine ( 3 ). 
       
     
     
       12. The internal combustion engine as claimed in  claim 1 , wherein the valve arrangement ( 50 ) is designed as a rotary disk valve. 
     
     
       13. The internal combustion engine as claimed in  claim 12 , wherein the rotary disk valve ( 50 ) includes, in addition to a diversion opening (X), a blow-off opening (Y). 
     
     
       14. The internal combustion engine as claimed in  claim 13 , wherein the blow-off opening (Y) is formed as a narrow slot on the slide valve ( 48 ). 
     
     
       15. The internal combustion engine as claimed in  claim 1 , wherein, with at turbocharger braking factors TBF Asym  smaller than 0.003, the valve arrangement ( 50 ) is in a blowoff position. 
     
     
       16. The internal combustion engine as claimed in  claim 1 , wherein, with turbocharger braking factors TBF Asym  at least equal to 0.003, the valve arrangement ( 50 ) is in a diversion position.

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